﻿/*
 * Copyright (c) 2000-2015 Tacke Consulting, Inc
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated 
 * documentation files (the "Software"), to deal in the Software without restriction, including without limitation 
 * the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, 
 * and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in all copies or substantial portions 
 * of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED 
 * TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF 
 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
 * DEALINGS IN THE SOFTWARE.
 * 
 */
using System;

using System.Collections.Generic;
using System.Text;
using Microsoft.Win32;
using System.Runtime.InteropServices;

namespace OpenNETCF.Media.DirectShow
{
    internal static class COMHelper
    {
        public const string CLSID_FILTERGRAPH = "{e436ebb3-524f-11ce-9f53-0020af0ba770}";
        public const string CLSID_FILTERGRAPH_NO_THREAD = "{e436ebb8-524f-11ce-9f53-0020af0ba770}";

        public static bool IsComObjectRegistered<T>()
        {
            return IsComObjectRegistered(typeof(T));
        }

        public static bool IsComObjectRegistered(Type comType)
        {
            if (comType == null) throw new ArgumentNullException("comType");

            var attribs = comType.GetCustomAttributes(typeof(GuidAttribute), false);

            if (attribs.Length != 1)
            {
                throw new ArgumentException("The provided type does not appear to have a GUID attribute.");
            }

            return IsComObjectRegistered(((GuidAttribute)attribs[0]).Value);
        }

        public static bool IsComObjectRegistered(string guid)
        {
            Guid g = new Guid(guid);

            RegistryKey key = null;
            try
            {
                key = Registry.ClassesRoot.OpenSubKey("CLSID\\" + guid + "\\InprocServer32");
                return key != null;
            }
            finally
            {
                if (key != null)
                {
                    key.Close();
                }
            }
        }
    }
}
